Expansion-bolt.



No. 768,283. PATENTED AUG. 23, 1904.

J. JENKINS. V

EXPANSION BOLT APPLIOATION FILED mm. 7, 1903.

N0 MODEL.

Hg. 2/. v

Inventor Witnesses:

Jbel Jenkins. 4 2/ JWMYQW UNITED STATES I Patented August 23, 1904.

PATENT OFFICE.

JOEL JENKINS, OF MONTGLAIR, NEw JERSEY, ASSIGNOR TO JENKINS MANUFACTURING COMPANY, OF BLOOMFIELD, N W JERSEY, A OOR- PORATION OF NEW JERSEY.

EXPANSION-BOLT.

SPECIFICATION forming part of Letters Patent N0. 768,283, dated. August 23, 1904.

Application filed December 7, 1903- Serial NO|184:,049| (N0 model.)

To all whom, it may concern.-

Be it known that -I, J on. JENKINS, a citizen of the United States, and a resident of Montclair, in the county of Essex and State of New Jersey, have invented an-Improvemcnt in Ex pansion-Bolts, of which the following descrip- .tion, in connection with the accompanying drawings, is a specification, like letters on the drawingsrepresenting like parts.

My invention relates to improvements in expansible bolts, which are employed in various connections, such as securing bolts in brick or stone surfaces or in fastening casters to furniture.

The character and scope of the invention will be best understood from a description of one specific embodiment thereof.

' aperture or a screw-thread to secure the bolt in position, and therefore it is necessary to provide some friction-holding means to securely anchor the bolt in a socket which hasbeen previously formed in the material of the wall or other surface. As usually constructed such expansion devices consist ofa short split sleeve or tube of suitable metal, such asbrass,

which is interposed between the head and a tapered nut on the extremities of the bolt to be. secured. The greatest diameter of the tapered nut is made approximately equal to that of the socket, so that when the bolt is turned substantially'confined to the extremity of the expansible sleeve, which is engaged between the nut and the wall of the-socket. Hence the greater portion of the holding-sleeve contributes nothing directly to the holding or anchoring function. To overcome this defect and at the same time to greatly lessen the cost of production, I have devised an improved expansible member consisting of a sleeve formed preferably, of spirally-coiled material. such as wire, or a fiat metal strip a of suitable length to extend between the head 6 of the boltb and the nut c on the threaded extremity thereof. The nut 0 is provided with-a central bore 0 and with a tapering perimeter, as

shown. A washer may be interposed beneath the head 6 of the bolt 6.

' When the parts are assembled and before the bolt Z) is turned up to any considerable extent in itsnutc, the device is inserted in a socket 0, formed for its reception in a wall or other surface'a Upon turning up the bolt the sleeve (4 is compressed lengthwise between the headbhandthe nut 0, whereupon it is flared or expanded by the/tapering face of the nut until it firmly engages the side wall of the socket 0. Upon further turning up,of the bolt the coils or sections of thespiral sleeve tend to ride. one upon another orto buckle,

and thereby firmly engage the-walls of the socket at numerous points intermediate of its extremities. Furthermore, if any indentations or irregularities exist in the walls of the socket this buckling of the sleeve causes the I coils or sections thereof to be projected into orbehind such irregularities, thus adding very materially to the holding or anchoring power of the device.

In the modification illustrated. in Fig. 4: the structure is shown as provided with a nut 0 of equal diameter throughout its length and the expansible sleeve as abutting squarely against the front face of the nut. In this as in the preferred form illustrated in Figs. shank, a nut and a sleeve of resilient round 1 to 3. coiled wire interposed between said head and Many changes may be made in the details nut. and in the relative arrangement of the parts In testimony whereofIhave signed my name 5 of the invention without altering the charaeto this specification in the presence of two sub- 5 ter or scope thereof. scribing witnesses.

Having described my invention, What I JOEL JENKINS. claim as new, and desire to secure by Letters lVitnesses: Patent, is NATHAN RUSSELL,

10 An expansion-bolt comprising a headed E. D. FARMER. 

